Abstract

The transport property of type manganite heterojunctions, composed of films (, 0.75, 0.85, and 1) and Nb-doped , has been experimentally studied. Different from junctions, the rectifying behavior of which is either thermionic emission/diffusion-dominated or tunneling-dominated; the electronic process in the junction undergoes a nonthermal to thermal transition as bias voltage increases, which is a feature emerging when Ca content exceeds and developing with the increase in . The two processes can be well described by the Shockley equation and the Newman equation, respectively. Possible mechanisms for this phenomenon are discussed.